Here is a question - I have tried to use the metronome in Garage Band - Now, the help says that it will count at the tempo of the project, but when I turn it on, it just follows a tempo of its own with no regard to the rhythm of the tracks - Anyone has any idea how to use it properly?

Smiles @Vixen... Yes Vixen is correct you have to set the tempo by going to the area to the right of the play & stop buttons, making sure the image is showing the metronome displaying key/tempo/signature...
You can change tempo there. But if you are just dragging in a pre made wav then you have to set the tempo up prior to dragging or else it will be off time. Because everything else in Gb is automatically set up to record whatever that tempo is set to. Was the rhythm tracks recorded on time? Are they apple loops or something else? A little more info might be able to pin point the issue if none of the above doesn't.

Thanks for the help - I can see now that I should set up the tempo prior to recording - What I was trying to do was adjust the metronome to an already recorded live track, thinking that the metronome will sort of adjust itself to the existing tempo - That's impossible, I now understand - So set the tempo of the metronome first, and then record - Got it - Thanks again

@tubinshlak No problem I figured that was what was going on. There is a couple ways to make the wav file adjust as well.
The first way is to highlight the wav and click CTRL-OPTION-G this should change the orange wav to purple but more important if you select follow tempo & pitch it should adjust when ever you adjust GB tempo. Big tempo changes will cause a wobble effect which then requires a better time-stretching algorithm. Audacity, apple loop utility, Melodyne and others can help with that. Second way is chopping up the wav into exactly 4 measure parts and dropping it into the loop area but again a drastic bpm change will cause the wobble effect. Just passing on the info is thanks enough, someone showed me and that's all I'm doing.
Moses